The research proposed is an examination of the timing of second and third births occurring to American women over the period 1955-1982, using data collected in Cycles I-III of the National Survey of Family Growth (NSFG). This data base provides a detailed history of birth and marital histories, as well as background characteristics, for a large number of women over a period during which birth timing in general was shifting rapidly. To be merged with the NSFG are a variety of aggregated or macro-level structural variables that provide the context within which fertility decisions are made. The research to be conducted will: 1) view birth timing as a dynamic process, recognizing that important determinants may shift at various durations from previous birth; 2) view birth timing as a function of several dimensions, including historical time (first/second-birth cohort), individual time (duration from previous birth) and various background and contextual factors; 3) estimate models separately for various race/ethnic groups; 4) provide estimates of the impact of important covariates in terms of intuitively interpretable standardized cumulative proportions of women surviving to various durations (from previous birth) without having a subsequent birth; 5) take into account the potentially important role that marital status plays in determining birth timing; and 6) provide estimates of survey effects in the NSFG. Linear logistic regression and odds ratios provide the basic methodological tools to be used in the analysis. Social scientists have documented the consequences of birth timing for marital dissolution, household structure, women's roles and socioeconomic well-being. This research will identify factors associated with changes in birth timing and will prove useful to both academics and policy makers.